Limited profile intervertebral implant with incorporated fastening and locking mechanism

ABSTRACT

In some embodiments, an intervertebral implant may include a body including a superior and an inferior surface. The implant may include a first channel extending from an anterior end towards the posterior end of the body. The implant may include a first anchor channel. The implant may include a first guide member positionable in the first channel. The implant may include a first anchor. When the first guide member moves from a first position to a second position the first anchor may be conveyed through the first anchor channel and couple the body to an adjacent vertebra. In some embodiments, the implant may include a first locking mechanism which inhibits, during use, the first guide member from moving from the second position to the first position upon activation of the first locking mechanism.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of co-pending U.S. application Ser. No. 15/360,399 filed Nov. 23, 2016, entitled LIMITED PROFILE INTERVERTEBRAL IMPLANT WITH INCORPORATED FASTENING AND LOCKING MECHANISM, which is a continuation in part of U.S. application Ser. No. 14/260,869 filed Apr. 24, 2014, entitled LIMITED PROFILE INTERVERTEBRAL IMPLANT WITH INCORPORATED FASTENING MECHANISM (issued as U.S. Pat. No. 9,517,144), each incorporated by reference herein in its entirety.

FIELD

The present disclosure generally relates to an intervertebral implant. More particularly, the disclosure generally relates to an intervertebral implant with an incorporated fastening mechanism including systems and methods for installing the intervertebral implant.

BACKGROUND

The human spine is a complex mechanical structure including alternating bony vertebrae and fibrocartilaginous discs that are connected by strong ligaments and supported by musculature that extends from the skull to the pelvis and provides axial support to the body. The intervertebral discs provide mechanical cushion between adjacent vertebral segments of the spinal column and include three basic components: the nucleus pulposus, the annulus fibrosis, and two vertebral end plates. The end plates are made of thin cartilage overlying a thin layer of hard cortical bone that attaches to the spongy, cancellous bone of the vertebral body. The annulus fibrosis forms the disc's perimeter and is a tough outer ring that binds adjacent vertebrae together. The vertebrae generally include a vertebral foramen bounded by the anterior vertebral body and the neural arch, which consists of two pedicles and two laminae that are united posteriorly. The spinous and transverse processes protrude from the neural arch. The superior and inferior articular facets lie at the root of the transverse process.

The human spine is highly flexible, capable of a high degree of curvature and twist in nearly every direction. Genetic or developmental irregularities, trauma, chronic stress, and degeneration, however, can result in spinal pathologies for which surgical intervention may be necessary. A disc may become damaged or diseased, reducing intervertebral separation. Reduction of the intervertebral separation may reduce a height of the disc nucleus, which may cause the annulus to buckle in areas where the laminated plies are loosely bonded. As the overlapping laminated plies of the annulus begin to buckle and separate, circumferential or radial annular tears may occur. Such disruption to the natural intervertebral separation may produce pain, which may be alleviated by removal of the disc and subsequently maintaining the natural separation of the vertebrae. In cases of chronic back pain resulting from a degenerated or herniated disc, removal of the disc becomes medically necessary.

In some instances, a damaged disc may be replaced with a disc prosthesis intended to duplicate the dynamic function of a natural spinal disc. In other cases, it may be desirable to fuse adjacent vertebrae of a human spine together after removal of a disc. This procedure is generally referred to as “intervertebral fusion” or “interbody fusion.” Intervertebral fusion has been accomplished with a variety of techniques and instruments. In some instances intervertebral fusion has been accomplished by placing structural bone or interbody fusion cage implants filled with bone graft material (e.g., morselized bone) within an intervertebral space where the spinal disc once resided. Fusion cage implants have been generally successful in promoting fusion and maintaining suitable disc height. Insertion of fusion cage implants, however, may be difficult. For example, fusion cages inserted from a posterior approach are generally limited in size by the space between the nerve roots which the implant is moved through during insertion. Moreover, as the distance between vertebral end plates is reduced, the height of the intervertebral space is reduced, thereby limited the size of implants introduced into the space, and often requiring distraction (e.g., spreading of the vertebrae) to achieve a suitable separation of the vertebrae.

Intervertebral fusion implants are typically inserted between adjacent vertebrae. Fasteners are typically deployed to couple the implant to one or more of the adjacent vertebrae. Problems occur due to the angle at which fasteners need to be employed through the implant into the adjacent vertebra relative to the patient's body. Fastener insertion instruments frequently interfere with a patient's body (e.g., chest, chin, etc.) due to the obtuse angles at which the instrument must be used relative to the implant and spine. These angles may make it difficult for the instrument to engage the fastener and/or apply sufficient pressure/force to the fastener using the instrument (e.g., especially when C2-C3 or C6-C7 levels are fused). It should be noted that fasteners which are positioned substantially perpendicular to vertebrae endplates provide better resistance to pull-out.

Accordingly, there is a desire to provide an implant technique that provides a simple and reliable solution for intervertebral fusion wherein fasteners are inserted substantially perpendicular to an endplate of a vertebra.

SUMMARY

In some embodiments, a spinal implant may include little to no profile extending beyond the vertebrae the implant is positioned between during use. In some embodiments, the implant may include at least one coupling mechanisms (in some embodiments, there may be at least two coupling mechanisms) incorporated into a preassembled implant. The coupling mechanism may function to couple the implant to the two vertebrae the implant is positioned between. The coupling mechanism may include an elongated member positionable in an opening in the implant, the elongated member may be inhibited from being removed from the opening. A first end of a fastening member may be coupled to the elongated member such that the fastening member is allowed to move relative to the elongated member. The fastening member may be curved. The coupling member may be activated, during use, by moving the elongated member from a first position to a second position. The first position may include a first end of the elongated member extending out from a first face of the implant and the second position may include the first end of the elongated member inserted in the implant such that the first end is substantially aligned with the first face. When the elongated member is moved from the first position to the second position a second end of the fastening member may be conveyed out of a channel in the implant wherein the opening extends out of a side of the implant adjacent to a vertebra during use. The second end of the fastening member may extend, during use, in the adjacent vertebra coupling the implant to the vertebrae.

In some embodiments, an intervertebral implant may include a body including a superior surface and an inferior surface. At least a portion of the superior surface may function to contact an endplate of an upper adjacent vertebra during use. The inferior surface may function to contact an endplate of a lower adjacent vertebra during use. The implant may include a first and a second channel extending from an anterior end to a posterior end of the body. The first and the second channels may be positioned on substantially opposing sides of the body. The implant may include a first and a second anchor channel. In some embodiments, an anchor channel may be curved. A first end of the first anchor channel may be coupled to the first channel adjacent the anterior end and a second end of the first anchor channel extends through the superior face of the body. A first end of the second anchor channel may be coupled to the second channel adjacent the anterior end and a second end of the second anchor channel extends through the inferior face of the body.

The implant may include a first and a second guide member positionable respectively in the first and the second channels. The guide members may be movable from a first position, a first end of the guide member extending from the anterior end of the body, to a second position, the first end of the guide member substantially flush with the anterior end of the body, during use. The implant may include a first and a second anchor coupled to the first end of the first and the second guide members respectively. When the first guide member moves from the first position to the second position the first anchor may be conveyed through the first anchor channel and couple the body to the upper adjacent vertebra during use. When the second guide member moves from the first position to the second position the second anchor may be conveyed through the second anchor channel and couple the body to the lower adjacent vertebra during use.

In some embodiments, substantially all of an outer perimeter of the body of the implant may be positioned within the outer perimeter of the upper and lower adjacent vertebrae after installation.

In some embodiments, the first guide member may include a coupling member adjacent the first end of the guide member. The first anchor may include an opening into which the coupling member is positionable. The coupling member may include a post.

In some embodiments, the body may include an opening extending from the superior surface to the inferior surface. The opening may hold biological material during use.

In some embodiments, the anterior end comprises an opening. The opening may function to couple to an insertion instrument.

In some embodiments, the implant may include a first locking mechanism which inhibits, during use, the first guide member from moving from the second position to the first position upon activation of the first locking mechanism. In some embodiments, the first locking mechanism may include a locking member and a resilient member. The resilient member may biase the locking member in a locked position.

In some embodiments, an anchor may include a plurality of ridges along at least one edge of the anchor. At least some of the plurality of ridges may be oriented in a direction substantially opposing to a direction of insertion of the first anchor in the adjacent vertebra during use.

In some embodiments, the first guide member may include an at least partially flexible second member. The second member may be positioned towards a distal end (e.g., posterior end) of the first guide member. The second member may flex toward the first guide member when force is applied to the second member. In some embodiments, the second member may include an engager. The engager may be positioned on a side of the second member opposite to the first guide member. The engager may interact, during use, with a first surface feature to inhibit movement of the first guide member in the first channel. The engager may interact, during use, with a first surface feature to inhibit movement of the first guide member in the first channel from the first position to the second position. The engager may interact, during use, with a first and/or a second surface feature to inhibit movement of the first guide member in the first channel. The engager may interact, during use, with a second surface feature to inhibit movement of the first guide member in the first channel from the second position to the first position.

In some embodiments, the first guide member may include a second member. The second member may be positioned coupled towards a distal end (e.g., posterior end) of the first guide member. In some embodiments, the second member may include an engager. The engager may interact, during use, with a first feature to inhibit movement of the first guide member in the first channel. The engager may interact, during use, with a first feature to inhibit movement of the first guide member in the first channel from the first position to the second position. The engager may interact, during use, with a first and/or a second surface feature to inhibit movement of the first guide member in the first channel. The engager may interact, during use, with a second surface feature to inhibit movement of the first guide member in the first channel from the second position to the first position.

In some embodiments, the first guide member may include a stop. The stop may be positioned towards a distal end of the first guide member and proximal to the second member. The stop may interact, during use, with a second feature to inhibit movement of the first guide member in the first channel. The stop may interact, during use, with a second feature to inhibit movement of the first guide member in the first channel from the first position to the second position. In some embodiments, the first and/or second feature may include an elongated member positioned at least partially in the first channel.

In some embodiments, the implant may include a first stop which functions to inhibit extraction of the first guide member from the first channel at the anterior end. The first stop may include a first pin.

In some embodiments, the implant may include a second stop positioned towards the anterior end of the body. The second stop may function to inhibit movement of the first guide member in the first channel. The second stop may function to inhibit movement of the first guide member in the first channel from the first position to the second position.

In some embodiments, the implant may include a third stop positioned towards the posterior end of the body. The third stop may function to inhibit movement of the first guide member in the first channel. The third stop may function to inhibit movement of the first guide member in the first channel from the second position to the first position.

In some embodiments, the implant may include a plurality of surface deformations positioned on the inferior surface and/or the superior surface. Surface deformations may include protrusions.

In some embodiments, a method may include implanting an intervertebral implant within an intervertebral space between endplates of adjacent vertebra. The method may include implanting an intervertebral implant between an upper adjacent vertebra and a lower adjacent vertebra such that a superior surface of a body of the intervertebral implant contacts an endplate of the upper adjacent vertebra and an inferior surface of the body contacts an endplate of the lower adjacent vertebra. The method may include conveying a first guide member through a first channel from a first position, a first end of the first guide member extending from an anterior end of the body, to a second position, the first end of the first guide member substantially flush with the anterior end of the body, during use. The method may include conveying a first anchor through a first anchor channel when the first guide member moves from the first position to the second position. A first end of the first anchor channel may be coupled to the first channel adjacent the anterior end and a second end of the first anchor channel extends through the superior face of the body. The method may include coupling the body to the upper adjacent vertebra using the first anchor.

In some embodiments, an intervertebral implant system may include an intervertebral implant and an anchor insertion instrument. In some embodiments, the intervertebral implant may include a body comprising a superior surface and an inferior surface. At least a portion of the superior surface may function to contact an endplate of an upper adjacent vertebra during use. The inferior surface may function to contact an endplate of a lower adjacent vertebra during use. The intervertebral implant may include a first anchor channel. A first end of the first anchor channel may be coupled to the anterior end and a second end of the first anchor channel extends through the inferior or superior face of the body. The intervertebral implant may include a first anchor positionable in the first anchor channel. The first anchor may include a first end and a second end. The first end may include a tapered end. The second end may include an elongated slot coupled to an expanded opening including a first dimension. The elongated slot comprises a first height and a first width. The first height may be greater than the first width.

In some embodiments, the anchor insertion instrument may include an elongated conduit. The anchor insertion instrument may include an elongated shaft positioned in the elongated conduit. The elongated shaft may be movable within the elongated conduit from a first position to a second position. The anchor insertion instrument may include a coupling member coupled to a distal end of the elongated shaft. The coupling member may include a second height and a second width. The second height may be greater than the second width. The second height may be less than the first height and the second height may be greater than the first width. The first dimension may be greater than the second height.

In some embodiments, a method may include implanting an intervertebral implant within an intervertebral space between endplates of adjacent vertebra. The method may include implanting an intervertebral implant between an upper adjacent vertebra and a lower adjacent vertebra such that a superior surface of a body of the intervertebral implant contacts an endplate of the upper adjacent vertebra and an inferior surface of the body contacts an endplate of the lower adjacent vertebra. The method may include inserting a coupling member of an anchor insertion instrument through an elongated slot and into an expanded opening coupled to the elongated slot in a second end of a first anchor, wherein the first anchor comprises a first end. The method may include rotating the coupling member within the expanded opening such that the coupling member is inhibited from extraction through the elongated slot of the first anchor. The method may include retracting an elongated shaft coupled, positionable in an elongated conduit, to the coupling member such that the second end of the first anchor abuts a distal end of the elongated conduit. The method may include conveying the first anchor through a first anchor channel in a body of the implant using the anchor insertion instrument. A first end of the first anchor channel may be coupled to the anterior end and a second end of the first anchor channel extends through the inferior or the superior face of the body. The method may include coupling the body to the upper or the lower adjacent vertebra using the first anchor.

In some embodiments, the method may include allowing articulation of the first anchor relative to the insertion instrument when the second end of the first anchor abuts a distal end of the elongated conduit. The second end of the first anchor may be substantially spherical. The distal end of the elongated conduit may be substantially concave.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the present invention may become apparent to those skilled in the art with the benefit of the following detailed description of the preferred embodiments and upon reference to the accompanying drawings.

FIG. 1 depicts a diagram of a side view of an embodiment of a spinal implant positioned between two vertebrae.

FIGS. 2A-B depict diagrams of a perspective view of an embodiment of a spinal implant with anchors in an unengaged position.

FIG. 3 depicts a diagram of a side view of an embodiment of a spinal implant with anchors in an unengaged position.

FIG. 4 depicts a diagram of a side view of an embodiment of a spinal implant with anchors in a partially engaged position.

FIG. 5 depicts a diagram of a side view of an embodiment of a spinal implant with anchors in an engaged position.

FIGS. 6A-C depict diagrams of a side view of several embodiments of a spinal implant with anchors in an unengaged position wherein the body is depicted as substantially transparent.

FIGS. 7A-B depict a diagram of a top view of embodiments of a portion of a spinal implant with anchors in an unengaged position wherein the body is depicted as substantially transparent.

FIG. 8 depicts a diagram of a top view of an embodiment of a portion of a spinal implant with anchors in an engaged position wherein the body is depicted as substantially transparent.

FIG. 9 depicts a diagram of an end view of an embodiment of an anterior end of a spinal implant with anchors in an engaged position.

FIG. 10 depicts a diagram of an end view of an embodiment of an posterior end of a spinal implant with anchors in an engaged position.

FIG. 11 depicts a diagram of a perspective view of an embodiment of an anchor for a spinal implant with an anchor insertion instrument with a coupling member.

FIG. 12 depicts a diagram of a perspective view of an embodiment of an anchor for a spinal implant with an anchor insertion instrument with a coupling member inserted in an elongated slot in a head of the anchor in an unengaged position.

FIG. 13 depicts a diagram of a perspective view of an embodiment of an anchor for a spinal implant with an anchor insertion instrument with a coupling member inserted in an elongated slot in a head of the anchor in an engaged position.

FIG. 14 depicts a diagram of a cross-sectional view of an embodiment of an anchor for a spinal implant with an anchor insertion instrument with a coupling member inserted in an elongated slot in a head of the anchor in an engaged position.

FIG. 15 depicts a diagram of a side view of an embodiment of an anchor for a spinal implant with an anchor insertion instrument with a coupling member inserted in an elongated slot in a head of the anchor in an engaged position with a second end of the anchor abutting a distal end of an elongated conduit.

FIG. 16 depicts a diagram of a side view of an embodiment of an anchor for a spinal implant with an anchor insertion instrument with a coupling member inserted in an elongated slot in a head of the anchor in an engaged position with a second end of the anchor abutting a distal end of an elongated conduit. The anchor has rotated relative to the insertion instrument with assistance from complementary surfaces on the anchor head and the distal end of the elongated conduit.

FIGS. 17A-B depict diagrams of a top rear perspective view of embodiments of a spinal implant with anchors in an engaged position.

FIGS. 18A-D depict diagrams of a rear view of embodiments of a spinal implant with anchors in an engaged position.

FIGS. 19A-B depict diagrams of a perspective view of embodiments of a locking member of a locking mechanism for a spinal implant.

FIGS. 20A-B depict diagrams of a side view of embodiments of a guide member for a spinal implant.

FIG. 21 depicts a diagram of a top view of an embodiment of an anchor for a spinal implant.

FIGS. 22A-B depict diagrams of a side view of embodiments of a spinal implant with anchors in an unengaged position.

FIGS. 23A-B depict diagrams of a top cross sectional view of embodiments of a spinal implant with anchors in an unengaged position.

FIGS. 24A-B depicts a diagram of a top cross sectional view of an embodiment of a spinal implant with anchors in an engaged position.

DETAILED DESCRIPTION

Definitions

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

The term “connected” as used herein generally refers to pieces which may be joined or linked together.

The term “coupled” as used herein generally refers to pieces which may be used operatively with each other, or joined or linked together, with or without one or more intervening members.

The term “directly” as used herein generally refers to one structure in physical contact with another structure, or, when used in reference to a procedure, means that one process effects another process or structure without the involvement of an intermediate step or component.

The term “intervertebral” as used herein generally refers to an area between adjacent vertebrae in the vertebral column. In some embodiments, intervertebral as used herein includes the area between the sacrum and the pelvis (or the sacroiliac joint).

The term “vertebral column” as used herein generally refers to the 24 articulating vertebrae, and nine fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs. The column houses and protects the spinal cord in its spinal canal, and is commonly called the spine or backbone. In some embodiments, vertebral column as used herein includes the sacroiliac joint connecting the sacrum and the pelvis.

Intervertebral Implant Embodiments:

In some embodiments, an intervertebral implant 100 may include a body 110 including a superior surface 120 and an inferior surface 130. FIG. 1 depicts a diagram of a side view of an embodiment of a spinal implant positioned between two vertebrae. At least a portion of the superior surface may function to contact an endplate 140 a of an upper adjacent vertebra 140 during use. The inferior surface may function to contact an endplate 150 a of a lower adjacent vertebra 150 during use.

FIGS. 2A-B depict diagrams of a perspective view of an embodiment of a spinal implant with anchors in an unengaged position. The implant may include a first 160 and a second channel 170 extending from an anterior end 180 to a posterior end 190 (e.g., depicted in FIG. 10) of the body 110. The first and the second channels may be positioned on substantially opposing sides of the body. The implant may include a first 200 and a second anchor channel 210. A first end 220 of the first anchor channel 200 may be coupled to the first channel 160 adjacent the anterior end 180 and a second end 230 of the first anchor channel may extend through the superior surface 120 of the body 110. A first end 240 of the second anchor channel 210 may be coupled to the second channel 170 adjacent the anterior end 180 and a second end 250 of the second anchor channel extends through the inferior surface 130 of the body 110.

The implant may include a first 260 and a second guide member 270 positionable respectively in the first 160 and the second channels 170. The guide members may be movable from a first position 280 a-b, first ends 290 a-b of the guide members extending from the anterior end of the body (e.g., depicted in FIGS. 2-3), to (e.g., the transition between the first and second positions depicted in FIG. 4) a second position 300 a-b, the first ends 290 a-b of the guide members substantially flush with the anterior end of the body (e.g., depicted in FIGS. 5 and 9), during use. In some embodiments, the first end 290 may function to inhibit movement of the guide member toward the posterior end. The first end 290 may function to inhibit movement of the guide member toward the posterior end due to interference of the first end with the anterior end (e.g., the first end is larger than the channels through which the guide members move). In some embodiments, guide members may include a shape which is complementary to a shape of the channels. Complementary shapes may function to inhibit movement of the guide members in the channels.

The implant may include a first 310 and a second anchor 320 coupled adjacently to the first ends 290 a-b of the first 260 and the second guide members 270 respectively. When the first guide member moves from the first position (e.g., depicted in FIGS. 2-3) to the second position (e.g., depicted in FIGS. 5 and 9) the first anchor may be conveyed through the first anchor channel and couple the body to the upper adjacent vertebra during use. When the second guide member moves from the first position to the second position the second anchor may be conveyed through the second anchor channel and couple the body to the lower adjacent vertebra during use. FIG. 3 depicts a diagram of a side view of an embodiment of the spinal implant 100 with anchors in an unengaged position. FIG. 4 depicts a diagram of a side view of an embodiment of the spinal implant 100 with anchors in a partially engaged position. FIG. 5 depicts a diagram of a side view of an embodiment of the spinal implant 100 with anchors in an engaged position. In some embodiments, anchors may include a shape which is complementary to a shape of the anchor channels. Complementary shapes may function to inhibit movement of the anchors in the anchor channels.

The anchors may be coupled to the guide members in a number of manners. The anchors may be coupled to the guide members such that the anchors are positionable relative to the guide members. The anchors may be coupled to the guide members such that the anchors may be conveyed through the anchor channel in a direction away from the guide members (e.g., such that the coupling point is not exposed to undue stress especially depending upon the materials the implant is formed from). In some embodiments, the anchors may be coupled to the guide members such that they are not directly attached but are inhibited from decoupling from one another. In some embodiments, the anchors may be coupled to the guide members such that they are directly attached and are inhibited from decoupling from one another.

In some embodiments, when the first guide member is in the first position with the anchors in an unengaged position a distal end of the anchor may be positioned in the anchor channel. Positioning of the distal end of the anchor in the anchor channel in combination with the coupling mechanism which couples the anchors to the guide members to inhibit disengagement of an anchor from a guide member.

In some embodiments, the first guide member 260 may include a coupling member 330 adjacent the first end 290 a of the guide member (e.g., depicted in FIGS. 7-8). The first anchor may include an opening 340 into which the coupling member is positionable (e.g., depicted in FIGS. 7-8). The coupling member may include a post. The opening may be sized relative to the post to allow movement of the anchor relative to the guide member.

In some embodiments, substantially all of an outer perimeter of the body of the implant may be positioned within the outer perimeter of the upper and lower adjacent vertebrae after installation (e.g., depicted in FIG. 1).

In some embodiments, the body may include an opening 350 extending from the superior surface to the inferior surface (e.g., depicted in FIGS. 2A-B). The opening may hold biological material during use. In some embodiments, opening 350 may be filled with a substance/material to facilitate bone growth/fusion. Once implant 100 is implanted, the opening may facilitate a column of bone growth between the adjacent vertebrae through the opening 350. In some embodiments, an opening (e.g., opening 350) may function as a graft window containing bone chips and/or materials which facilitate tissue (e.g., bone) growth.

In some embodiments, the implant 100 may include only one anchor. The implant may include only one guide member and anchor combination. The implant may include one or more openings extending from the superior surface to the inferior surface for holding biological material. The anchor may be substantially centered in the body of the implant allowing biological material openings on either side of the anchor.

In some embodiments, the implant 100 may include two anchors coupled to a single guide member (e.g., as depicted in FIG. 6C). The first anchor may be coupled to an upper portion of a guide member and the second anchor may be coupled to an opposing lower portion of the guide member. As the guide member is advanced the anchors may penetrate the endplates of adjacent vertebrae, such that the first anchor couples the implant to the superior vertebra and the second anchor couples the implant to the inferior vertebra. Such an embodiment may require an implant with an increased thickness to accommodate such a double anchor configuration. Although the embodiment in FIG. 6C depicts the anchors as being positioned on one side of the implant, the anchors may be positioned in a more central location when there is only one guide member (e.g., with one or more openings on either one or both sides of the guide member through the body for organic material).

In some embodiments, the anterior end may include a coupling mechanism 360. The coupling mechanism may function to couple to an insertion instrument. The coupling mechanism may include an opening. The opening may include an opening with a complementary shape to a portion of an insertion instrument. The opening may form a friction fit with the portion of the insertion instrument. In some embodiments, the coupling mechanism may include multiple openings (e.g., three openings as depicted in FIG. 9).

In some embodiments, the implant 100 may include a first stop 370 which functions to inhibit extraction of the first guide member 260 from the first channel 160 at the anterior end 180 (e.g., depicted in FIG. 6A-B). The first stop 370 may include a first pin. The first stop may include a first pin positioned horizontally. The first guide member 260 may include a second end 380 shaped such that the second end is inhibited from moving past the first stop when the first guide member moves toward the anterior end 180. Portions of the first guide member adjacent the first end 290 a may be shaped such that the portions of the first guide member may move past the first stop allowing the first guide member to move towards the posterior end 190.

In some embodiments, the second end 380 of the first guide member 260 may include a portion 380 a shaped such that the second end is inhibited from moving past the first stop when the first guide member moves toward the posterior end 190 (e.g., depicted in FIG. 6B). The first stop may function to inhibit movement of the first guide member in the first channel. The first stop and the second end may function to inhibit activation of the anchors until desired by a user.

In some embodiments, the first ends 290 a-b of the guide members may be shaped such that the first end is inhibited from moving beyond the anterior end 180 of the body 110 inhibiting movement of the first guide member towards the posterior end 190. The first end of the guide members may fit within a recess 375 of the anterior end and as such be shaped to fit substantially flush with the anterior end (e.g., depicted in FIGS. 6 and 9). The first stop 370 and the first end may function to limit movement of the first guide member within a specified range.

In some embodiments, the implant may include a second stop 390 positioned towards the anterior end of the body. The second stop may function to inhibit movement of the first guide member in the first channel. The second stop may function to inhibit movement of the first guide member in the first channel from the first position to the second position. In some embodiments, the second stop may function to inhibit movement of the first guide member in the first channel from the second position to the first position. The second stop may include a second pin. The second pin may be positioned vertically. The second stop may interact with a first recess 400 in a side of a distal end of the first guide member (e.g., depicted in FIG. 7A). The second stop and the first recess may form a friction fit to inhibit movement of the first guide member when the first guide member is in the first position (i.e., when the anchors are in an unengaged position). The second stop and the first recess may function inhibit activation of the anchors until desired by a user.

As the first guide member moves toward the posterior end of the body of the implant, the second stop 390 may interact with a second recess 410 in a side of a proximal end of the first guide member (e.g., depicted in FIG. 8). The second stop and the second recess may form a friction fit to inhibit movement of the first guide member when the first guide member is in the second position (i.e., when the anchors are in an engaged position).

In some embodiments, the implant may include a third stop 420 positioned towards the posterior end of the body. The third stop may function to inhibit movement of the first guide member in the first channel. The third stop may function to inhibit movement of the first guide member in the first channel from the second position to the first position. In some embodiments, the third stop may function to inhibit movement of the first guide member in the first channel from the first position to the second position. The third stop may include a third pin. The third pin may be positioned vertically. The third stop may interact with the first recess 400 in a side of the distal end of the first guide member (e.g., depicted in FIG. 8). The third stop and the first recess may form a friction fit to inhibit movement of the first guide member when the first guide member is in the second position (i.e., when the anchors are in an engaged position).

In some embodiments, the implant may include all of the features described herein (at least those which do not interfere with one another). In some embodiments, the implant may include only some of the features described herein (e.g., the implant may not include second stop 390 as depicted in FIG. 7B). In some embodiments, stops may function as more of a hard stop or a soft stop. For example, stop 370 may function as a hard stop as far as far as inhibiting extraction of a guide member. To overcome or move past a hard stop may require disassembling and/or damaging at least a portion of the implant. The first end 290 may function as a hard stop to inhibit movement of the guide member toward the posterior end. While stop 370 may function as a soft stop as far as inhibiting movement of a portion of a guide member past the first stop during insertion of the guide member into a channel in the implant (e.g., as depicted in FIGS. 6B-C). A soft stop may function to only provide resistance to movement of a portion of the implant during normal operation of the implant during use.

Superior and/or inferior surfaces of the implant may include various features to facilitate engagement of the surfaces with endplates of adjacent vertebrae. In some embodiments, the implant may include a plurality of surface deformations positioned on the inferior surface and/or the superior surface. Surface deformations may include protrusions. For example (e.g., depicted in FIG. 2B) superior surface of body 110 may include protrusions (e.g., teeth) 430 extending there from. During use, teeth 430 may extend/penetrate into adjacent boney structure of the upper and lower adjacent vertebrae. Such penetration may help to fix a position of body 110, and, thus implant 100, relative to the vertebrae. Fixing or otherwise stabilizing the implant may reduce the likelihood of implant 100 being expelled from within the intervertebral space, and may promote bone attachment to and through implant 100.

In some embodiments, protrusions 430 may include unidirectional teeth that facilitate forward insertion of the members, but inhibit back-out of the members. For example, in the illustrated embodiment, teeth 430 include a ramped leading surface 430 a and a substantially vertical trailing edge 430 b (e.g., depicted in FIG. 2B). Thus, forward advancement of the members may be facilitated as boney structure of the vertebrae slides over ramped leading surface 430 a of teeth 430 and backward advancement may be inhibited by substantially vertical trailing edge 430 b hooking into or otherwise engaging the boney structure of the vertebrae.

In some embodiments, one or more portions of the implant 100 may include markers 440 (e.g., depicted in FIGS. 2A and 7-8). Markers may be used to assess a position of one or more portions of the implant during implantation in a subject. A portion of the implant may include none, one or multiple markers. Markers may provide radiographic opacity. Markers may be biocompatible. Markers may be of any size or shape. In some embodiments, a system may have multiple markers with different shapes in order to more easily identify different portions of the system and/or an orientation of one or more portions of the implant. In some embodiments, one or more markers may be formed from gold or tantalum.

In some embodiments, a method may include implanting an intervertebral implant within an intervertebral space between endplates of adjacent vertebra. The method may include implanting an intervertebral implant between an upper adjacent vertebra and a lower adjacent vertebra such that a superior surface of a body of the intervertebral implant contacts an endplate of the upper adjacent vertebra and an inferior surface of the body contacts an endplate of the lower adjacent vertebra. The method may include conveying a first guide member through a first channel from a first position, a first end of the first guide member extending from an anterior end of the body, to a second position, the first end of the first guide member substantially flush with the anterior end of the body, during use. The method may include conveying a first anchor through a first anchor channel when the first guide member moves from the first position to the second position. A first end of the first anchor channel may be coupled to the first channel adjacent the anterior end and a second end of the first anchor channel extends through the superior face of the body. The method may include coupling the body to the upper adjacent vertebra using the first anchor.

In some embodiments, an intervertebral implant system may include an intervertebral implant 100 and an anchor insertion instrument 500. In some embodiments, the intervertebral implant may include a body comprising a superior surface and an inferior surface. At least a portion of the superior surface may be function to contact an endplate of an upper adjacent vertebra during use. The inferior surface may function to contact an endplate of a lower adjacent vertebra during use. The intervertebral implant may include a first anchor channel. A first end of the first anchor channel may be coupled to the anterior end and a second end of the first anchor channel extends through the inferior or superior face of the body. The intervertebral implant may include a first anchor 510 positionable in the first anchor channel. The first anchor may include a first end 520 and a second end 530. The first end may include a tapered end. The second end may include an elongated slot 540 coupled to an expanded opening 550 including a first dimension (e.g., depicted in FIG. 11). The elongated slot comprises a first height and a first width. The first height may be greater than the first width.

In some embodiments, the anchor insertion instrument 500 may include an elongated conduit 560. The anchor insertion instrument may include an elongated shaft 570 positioned in the elongated conduit 560 (e.g., depicted in FIG. 11). The elongated shaft may be movable within the elongated conduit from a first position (e.g., as depicted in FIG. 14) to a second position (e.g., as depicted in FIG. 15). The anchor insertion instrument may include a coupling member 580 coupled to a distal end 590 of the elongated shaft. The coupling member may include a second height and a second width. The second height may be greater than the second width. The second height may be less than the first height and the second height may be greater than the first width. The first dimension may be greater than the second height. The coupling member 580 may be dimensioned to fit through the elongated slot 540 when the longitudinal axis of the coupling member is in alignment with the elongated slot (e.g., as depicted in FIG. 12). Upon the coupling member 580 being positioned into the expanded opening 550 the coupling member and expanded opening are dimensioned relative to one another to allow the coupling member to be rotated within the expanded opening. The coupling member may be rotated using the elongated shaft coupled to the coupling member. Upon the coupling member be rotated such that the longitudinal axis of the coupling member is misaligned with the elongated slot (e.g., as depicted in FIG. 13) the coupling member is inhibited from being extracted back through the elongated slot.

Upon coupling the coupling member to the anchor, the elongated shaft may be retracted within the elongated conduit from the first position to the second position (e.g., as depicted in FIGS. 14-15). In some embodiments, the elongated shaft may be biased towards the second position (e.g., spring loaded). Retracting the elongated shaft to the second position abuts the second end of the anchor to a distal end of the elongated conduit. The second end of the anchor and the distal end of the elongated conduit may include complementary shaped surfaces. In some embodiments, the second end of the anchor includes a convex surface and the distal end of the elongated conduit includes a concave surface complementary to the convex surface. The spherical head of the curved anchor rotates about the concave tip of the distal end of the elongated conduit (e.g., as depicted in FIG. 16). The spherical head of the anchor and the concave surface of the distal end of the elongated conduit allows for articulation of the anchor about the inserter instrument. When anchor engages the screw hole, which is angled toward the vertebral body, the anchor rotates about the distal end of the elongated conduit's concave tip and allows the anchor to be impacted perpendicular to the anterior end.

In some embodiments, the anchor insertion instrument 500 may include an aligner 600. The aligner may function to inhibit rotational movement of the anchor relative to the conduit 560 when the second end of the anchor abuts the distal end of the elongated conduit. The aligner 600 may be positionable in the elongated slot 540 when the second end of the anchor abuts the distal end of the elongated conduit. When the aligner 600 is positioned in the elongated slot the anchor is inhibited from rotating relative to the conduit 560 inhibiting disengagement of the coupling member 580 from the anchor 510 except when desired by the user.

In some embodiments, a method may include implanting an intervertebral implant within an intervertebral space between endplates of adjacent vertebra. The method may include implanting an intervertebral implant between an upper adjacent vertebra and a lower adjacent vertebra such that a superior surface of a body of the intervertebral implant contacts an endplate of the upper adjacent vertebra and an inferior surface of the body contacts an endplate of the lower adjacent vertebra. The method may include inserting a coupling member of an anchor insertion instrument through an elongated slot and into an expanded opening coupled to the elongated slot in a second end of a first anchor, wherein the first anchor comprises a first end. The method may include rotating the coupling member within the expanded opening such that the coupling member is inhibited from extraction through the elongated slot of the first anchor. The method may include retracting an elongated shaft coupled, positionable in an elongated conduit, to the coupling member such that the second end of the first anchor abuts a distal end of the elongated conduit. The method may include conveying the first anchor through a first anchor channel in a body of the implant using the anchor insertion instrument. A first end of the first anchor channel may be coupled to the anterior end and a second end of the first anchor channel extends through the inferior or the superior face of the body. The method may include coupling the body to the upper or the lower adjacent vertebra using the first anchor.

In some embodiments, the method may include allowing articulation of the first anchor relative to the insertion instrument when the second end of the first anchor abuts a distal end of the elongated conduit. The second end of the first anchor may be substantially spherical. The distal end of the elongated conduit may be substantially concave.

Locking Intervertebral Implant Embodiments:

At least portions of embodiments described herein below may combined in any numbers of ways with one or more portions of embodiments of the implant described herein below. In some embodiments, the implant (e.g., depicted in FIGS. 17-18D) may include a first locking mechanism 700 (e.g., depicted in FIGS. 19A-B) which inhibits, during use, the first guide member 260 from moving from the second position (e.g., depicted in FIGS. 24A-B) to the first position (e.g., depicted in FIGS. 23A-B) upon activation of the first locking mechanism. In some embodiments, the first locking mechanism 700 may include a locking member 710 and a resilient member 720 (e.g., depicted in FIGS. 19A-B). The resilient member may bias the locking member in a locked position. In some embodiments, the locking member 710 may function as a visual locking indicator for a user who is implanting the implant 100. A position of the locking member 710 may allow a user to visually determine whether or not the locking member has been activated and as such if the implant has been properly deployed.

The resilient member 720 may be able to recoil or spring back into shape after bending, stretching, or being stretched. The resilient member may be formed from a biocompatible material which returns to its original shape upon being distorted, for example, as a result of external forces. The resilient member 720 may return to its original form upon distortion due to the innate properties of the materials used to form the resilient member. The resilient member may be in the form of a spring or spring like member.

The resilient member 720 may be coupled to the locking member 710 of the locking mechanism 700. The resilient member 720 may be coupled to the body 110 of the implant 100. In some embodiments, the resilient member 720 may be positioned in an opening 730 in a proximal end of the body of the implant. The opening may be sized to compress the resilient member within the opening and hold the resilient member in via, for example, a friction fit. In some embodiments, a coupling member 740 (e.g., depicted in FIGS. 19A-B) may form a portion of the locking mechanism 700 which may, for example, inhibit the resilient member from exiting the opening 730 (e.g., depicted in FIG. 18A-D). The locking member 710 may be coupled to the resilient member such that at least a portion of the locking member extends outside of the opening 730. The locking member may slide along a proximal surface 180 (e.g., in some embodiments an anterior end during use) of the body 110 of the implant 100 (e.g., depicted in FIG. 18A-D). The resilient member 720 may bias the locking member 710 in a locked position such that at least a portion of the locking member covers an opening in the proximal surface 180 of the body 110 of the implant 100. The opening may form a posterior portion of the channel 160. When in the locked position the locking member inhibits, during use, the guide member 260 from moving from the second position (e.g., depicted in FIGS. 24A-B), the first end 290 a of the guide member substantially flush with the proximal or anterior end 180 of the body 110, to the first position (e.g., depicted in FIGS. 23A-B), a first end of the guide member extending from the proximal or anterior end of the body, inhibiting the anchor 310 from becoming unengaged from an adjacent vertebrae when the anchor is deployed (e.g., depicted in FIGS. 24A-B).

In some embodiments, the locking member may include an angled edge 715 (e.g., depicted in FIGS. 19A-B) on an exterior (relative to the implant) face and on a side of the locking member facing the opening in the proximal surface of the body of the implant forming a portion of the channel. The first end of the guide member may include an angled edge 295 a (e.g., as depicted in FIGS. 20A and 23B) on an interior (relative to the implant) face and on a side of the first end of the guide member facing the angled edge of the locking member. The two angled surfaces may be complementary such that when the guide member is moved from the first position (e.g., as depicted in FIGS. 23A-B) to the second position (e.g., as depicted in FIGS. 24A-B) the angled surface of the first end of the guide member translates the longitudinal force of the guide member to a lateral force for the locking member. The lateral force moves the locking member form a locked position to an unlocked position allowing the first end of the guide member to pass by the locking member. Upon the first end of the guide member passing by the locking member, the resilient member may provide a lateral force counter to the first lateral force moving the locking member from the unlocked position to the locked position (e.g., such that at least a portion of the locking member covers a portion of the channel and the first end of the guide member.

In some embodiments, the first ends 290 a-b of the guide members may be shaped such that the first end is inhibited from moving substantially beyond the proximal (e.g., anterior) end 180 of the body 110 inhibiting movement of the first guide member towards the distal (e.g., posterior) end 190. The first end of the guide members may fit within a recess 375 of the anterior end and as such be shaped to fit substantially flush with the anterior end (e.g., depicted in FIGS. 23A-24B).

In some embodiments, the first guide member 260 may include an at least partially flexible second member 800 (e.g., as depicted in FIGS. 20A-B). The second member 800 may be positioned towards a distal end 190 (e.g., posterior end) of the first guide member 260. In some embodiments, the second member may flex toward the first guide member when force is applied to the second member (e.g., as depicted in FIG. 20A, there may be an opening 810 between the distal end 190 of the first guide member 260 and the second member 800 allowing the second member 800 room to move). In some embodiments, the second member may be more rigid (e.g., as depicted in FIG. 20B).

In some embodiments, the second member 800 may include an engager 820 (e.g., as depicted in FIGS. 20A-B). In some embodiments, the engager may be positioned on a side of the second member opposite to the first guide member (e.g., as depicted in FIG. 20A). The engager may interact, during use, with a first surface feature 830 to inhibit movement of the first guide member 260 in the first channel 160. The engager may interact, during use, with a first surface feature to inhibit movement of the first guide member in the first channel from the first position to the second position. The engager may interact, during use, with a first and/or a second surface feature to inhibit movement of the first guide member in the first channel. The engager 820 may interact, during use, with a second surface feature 840 to inhibit movement of the first guide member in the first channel from the second position to the first position.

In some embodiments, the engager 820 may include an elevated feature extending from the second member 800. In some embodiments, the first 830 and/or second 840 feature along an interior surface of the channel 160 may include an opening or depression. The opening or depression may have a complementary shape to the engager. As such, in some embodiments, the second member may flex towards the guide member while moving through the channel (e.g., as the engager may be too large to move through the channel without the second member flexing inward). The surface feature may engage the engager and inhibit further movement through the channel at least without additional force being applied by the user. The surface feature may allow the second member to flex outward, away from the guide member as the engager engages (e.g., enters) the surface feature.

In some embodiments, the opening and/or the engager may be shaped such that the engager's exit from the opening is facilitated when the guide member is moving in a first direction relative the engager's exit from the opening when the guide member is moving in an opposing second direction. For example, when the guide member is moved from a first position to a second position the engager may move out of the first surface feature and into the second surface feature easier relative to (hence requiring more force exerted by a user) moving the guide member from the second position to the first position (hence biasing the implant in an engaged state with adjacent vertebrae during use).

In some embodiments, the engager may be positioned on a side of the second member facing the first guide member (e.g., as depicted in FIG. 20B). The engager may interact, during use, with a first feature 835 (the first feature may include an elongated member stretching across at least a portion of the first channel) to inhibit movement of the first guide member 260 in the first channel 160. The engager may interact, during use, with a first feature to inhibit movement of the first guide member in the first channel from the second position to the first position. The engager may be sloped to allow the engager to more easily slide over the first feature when the first guide member moves from the first position to the second position. However, upon the first guide member reaching the second position or at least substantially adjacent the second position the engager may engage the first feature to inhibit movement of the first guide member in the first channel from the second position to the first position. The engager may interact, during use, with a first feature to inhibit movement of the first guide member in the first channel.

In some embodiments, an engager 825 may interact, during use, with a second feature 845 (the first feature may include an elongated member stretching across at least a portion of the first channel) to inhibit movement of the first guide member in the first channel from the first position to the second position. In some embodiments, the engager 825 may interact with the second feature 845 only to slightly inhibit movement of the first guide member in the first channel from the first position to the second position such that the first guide member is not accidentally deployed prematurely during surgery.

In some embodiments, at least a portion of the second member 800 may interact with the second feature 845 to inhibit extraction of the first guide member from the first channel (e.g., as depicted in FIG. 23B, out of the proximal (e.g., anterior) end 180 of the body 110).

In some embodiments, the first guide member 260 may include a coupling member 330 adjacent the first end 290 a of the guide member (e.g., depicted in FIGS. 20-21). The first anchor 310 may include an opening 340 into which the coupling member is positionable (e.g., depicted in FIG. 21). The coupling member may include a post. The opening may be sized relative to the post to allow movement of the anchor relative to the guide member.

In some embodiments, coupling member 330 may interact with second feature 845 to inhibit movement of the first guide member 260 from moving towards the posterior end 190 past the second position.

In some embodiments, an anchor may include a plurality of ridges 900 along at least one edge 910 of the anchor 310 (e.g., depicted in FIG. 21). In some embodiments, an anchor may include a plurality of ridges along at least two opposing edges of the anchor. At least some of the plurality of ridges may be oriented in a direction substantially opposing to a direction of insertion of the first anchor in the adjacent vertebra during use (e.g., depicted in FIG. 21). The orientation of the ridges may facilitate insertion of the first anchor in adjacent vertebra while inhibiting extraction of the first anchor from adjacent vertebra.

Superior and/or inferior surfaces of the implant may include various features to facilitate engagement of the surfaces with endplates of adjacent vertebrae. In some embodiments, the implant may include a plurality of surface deformations positioned on the inferior surface and/or the superior surface. Surface deformations may include protrusions. For example (e.g., depicted in FIGS. 22A-B) superior surface 120 and/or inferior surface 130 of body 110 may include protrusions (e.g., teeth) 430 extending there from. During use, teeth 430 may extend/penetrate into adjacent boney structure of the upper and lower adjacent vertebrae. Such penetration may help to fix a position of body 110, and, thus implant 100, relative to the vertebrae. Fixing or otherwise stabilizing the implant may reduce the likelihood of implant 100 being expelled from within the intervertebral space, and may promote bone attachment to and/or through implant 100.

In some embodiments, protrusions 430 may include unidirectional teeth that facilitate forward insertion of the members, but inhibit back-out of the members. For example, in the illustrated embodiment, teeth 430 include a ramped leading surface 430 a and a substantially vertical trailing edge 430 b (e.g., depicted in FIGS. 22A-B). Thus, forward advancement of the members may be facilitated as boney structure of the vertebrae slides over ramped leading surface 430 a of teeth 430 and backward advancement may be inhibited by substantially vertical trailing edge 430 b hooking into or otherwise engaging the boney structure of the vertebrae.

In some embodiments, the body may include an opening 350 extending from the superior surface to the inferior surface (e.g., depicted in FIGS. 23-24). The opening may hold biological material during use. In some embodiments, opening 350 may be filled with a substance/material to facilitate bone growth/fusion. Once implant 100 is implanted, the opening may facilitate a column of bone growth between the adjacent vertebrae through the opening 350. In some embodiments, an opening (e.g., opening 350) may function as a graft window containing bone chips and/or materials which facilitate tissue (e.g., bone) growth. The opening 350 depicted in FIGS. 23-24 may include an increased radius relative to the opening 350 depicted in FIGS. 2A-B. The increased radius may provide for increased strength of the implant.

In some embodiments, one or more portions of the implant 100 may include markers 440 (e.g., depicted in FIGS. 22-24). Markers may be used to assess a position of one or more portions of the implant during implantation in a subject. A portion of the implant may include none, one or multiple markers. Markers may provide radiographic opacity. Markers may be biocompatible. Markers may be of any size or shape. In some embodiments, a system may have multiple markers with different shapes in order to more easily identify different portions of the system and/or an orientation of one or more portions of the implant. In some embodiments, one or more markers may be formed from gold or tantalum.

In some embodiments, the implant 100 may be made available in multiple sizes to accommodate different patients. For example, FIGS. 18B and D depicts an embodiment of implant 100 which is thicker in dimension than the embodiment depicted in FIGS. 18A and B.

In this patent, certain U.S. patents, U.S. patent applications, and other materials (e.g., articles) have been incorporated by reference. The text of such U.S. patents, U.S. patent applications, and other materials is, however, only incorporated by reference to the extent that no conflict exists between such text and the other statements and drawings set forth herein. In the event of such conflict, then any such conflicting text in such incorporated by reference U.S. patents, U.S. patent applications, and other materials is specifically not incorporated by reference in this patent.

Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims. 

1-14. (canceled)
 15. A method of implanting an intervertebral implant within an intervertebral space between endplates of adjacent vertebra, comprising: implanting an intervertebral implant between an upper adjacent vertebra and a lower adjacent vertebra such that a superior surface of a body of the intervertebral implant contacts an endplate of the upper adjacent vertebra and an inferior surface of the body contacts an endplate of the lower adjacent vertebra; conveying a first guide member through a first channel from a first position, a first end of the first guide member extending from an anterior end of the body, to a second position, the first end of the first guide member substantially flush with the anterior end of the body, during use; conveying a first anchor through a first anchor channel when the first guide member moves from the first position to the second position, wherein a first end of the first anchor channel is coupled to the first channel adjacent the anterior end and a second end of the first anchor channel extends through the superior and/or the inferior face of the body; coupling the body to at least one of the adjacent vertebrae using the first anchor; and inhibiting the first guide member from moving from the second position to the first position upon activation of a locking mechanism.
 16. (canceled)
 17. The method of claim 15, further comprising biasing a locking member of the locking mechanism in a locked position using a resilient member of the locking mechanism.
 18. (canceled)
 19. The method of claim 15, further comprising: engaging a first feature using an engager of a second member coupled towards a distal end of the first guide member; and inhibiting movement of the first guide member in the first channel using the engaged engager.
 20. (canceled)
 21. The method of claim 15, further comprising: engaging a first feature using an engager of a second member coupled towards a distal end of the first guide member; inhibiting movement of the first guide member in the first channel from the second position to the first position using the engaged engager; and interacting a stop with a second feature such that movement of the first guide member is inhibited in the first channel from the first position to the second position, wherein the stop is positioned towards a distal end of the first guide member and proximal to the second member.
 22. The method of claim 21, wherein the first and/or second feature comprises an elongated member positioned at least partially in the first channel. 23-25. (canceled)
 26. The method of claim 15, further comprising coupling an insertion instrument to an opening in the anterior end of the body. 